<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
<script>
    var admin=prompt('请输入用户名：');
    var pass=prompt('请输入密码：');
    if(admin=='admin'&&pass=='123'){
        alert('登录成功');
    }                     
    else{
        alert('用户名密码错误');
    } 

</script>
</body>
</html>